He did. He came back about 6 years later because immigration was up not down.

UKIP was dead when BoJo was in power. But of course, the Tories under May, BoJo and Sunak amped up immigration to record levels, so now there's a stronger case for Farage to contest. While UKIP was largely about Euroscepticism, Reform has openly racist undertones in their pitch to voters.